Writing to and reading data from Flash using IAP

Here you can see functions I'm using to store data into Flash, but I'm getting data erased after power reset, so it's still in RAM not in Flash.

#define   OFFSET_ADDRESS                     0x00030000                                                                                        
#define   OFFSET_VERSION                     0x00030002
#define   OFFSET_SERIAL                      0x00030004  

    void read_from_flash (void)   {                     

        BYTE i, *pok_add, *pok_ver, *pok_serial_no;

        pok_add = (BYTE *)OFFSET_ADDRESS;
        display_address = *pok_add;
        delay_1_ms();
        if ((display_address > MAX_OUTDOOR_DISPLAY_ADDRESS) || (display_address < MIN_OUTDOOR_DISPLAY_ADDRESS))  display_address = UNI_ADDRESS;


        pok_ver = (BYTE *)OFFSET_VERSION;
        version = *pok_ver;
        delay_1_ms();
        if (version > MAX_FW_VERSION)        version = 0;                        

        for (i=0;i<8;i++)     {
            pok_serial_no = (BYTE *)OFFSET_ADDRESS;
            serial_no[i] = *pok_serial_no++;
            delay_1_ms();
        }
        for (i=0;i<8;i++)         if (serial_no[i] > 9)   serial_no[i] = 0;       

    }


    void write_to_flash (void)    {                     
    BYTE i;

        iap_copy_to_flash(&display_address, OFFSET_ADDRESS, 1);
        delay_1_ms();

        iap_copy_to_flash(&version, OFFSET_VERSION, 1);
        delay_1_ms();

        for (i=0;i<8;i++)     {
            iap_copy_to_flash(&serial_no[i], OFFSET_VERSION+i, 1);
            delay_1_ms();
            }

        }

Question is where I'm wrong? Sectors in a LPC178x/177x device http://www.nxp.com/documents/user_manual/UM10470.pdf on page 883. Maybe I don't write and read data properly so it's still located in RAM.